Patent GB-1090132-A (GB)
Title: Improvements in and relating to subscriber telephone meters
Inventor: YOUNG ANDREW
IPC: H04M17/02
Filed: 1963-04-29
Abstract: 1,090,132. Prepayment apparatus for telephone subscribers. ASSOCIATED AUTOMATION Ltd., and SMITH'S INDUSTRIES Ltd. April 29, 1964 [April 29, 1963], No. 16826/63. Heading H4K. [Also in Divisions F2 and G4] A telephone set, Fig. 10, is provided with a credit-debit mechanism, coins inserted in a slot 3 enabling the mechanism to be set into credit as indicated at 4 and pulses sent from the exchange returning the mechanism towards debit, non- emergency calls being cut off on the expiry of credit or on the expiry of credit plus a permitted amount of debit, but emergency calls being made and incoming calls being received regardless of the amount in credit or debit. The coins collected by the set may be made available to the subscriber who uses the mechanism to provide sufficient money to defray the cost as presented by a bill compiled from the normal meter records. A switch may be provided to isolate the coin mechanism thereby providing a normal telephone set. A coin inserted into coin slot 3 is held in suspense at the bottom of shoot 3A, Fig. 1, by a pivoted abutment 3B. A manual bar 2, Fig. 1, pivoted on spindle 2A, Fig. 2, is depressed to gain acceptance of the coin. Depression of the bar 2 pulls on a chain, of which only the top portion is shown in Fig. 1, to rotate gear segment 5A. A pawl ensures a full throw of the segment which drives a gear 6 to wind a spring motor and drives a gear 7 to transport a coin carriage 9 from the position shown to a position in alignment with the end of coin shoot 3A. The carriage deflects the abutment 3B and receives the coin in a pocket defined by walls 9A and 9B. On release of the manual bar 2 the spring motor associated with the gear 6 restores the mechanism at a speed controlled by regulator 80 in mesh with a gear 6A fast with the gear 6. In the course of its transportation by the coin carriage 9 the coin, depending on its diameter, strikes an abutment 25A, 25B or 25C, to give a rotation to a gear 8 which corresponds with the value of the coin. The coin is released to a coin box when the carriage engages a lever system 9D, 9E. The rotation of the gear 8 is translated by a two-lobed cam 10B into a number of reciprocations of a ratchet drive arm 11, the ratchet 11F of which steps the credit input wheel of a standard differential epicyclic quantity mechanism, see Fig. 8 (not shown). The credit-debit indicator is driven from the spindle of the differential and by the intervention of a magnifying lever system it runs faster when in debit than when in credit. The differential spindle also drives a lostmotion coupling 20, Figs. 8 and 11 (not shown). The lost motion coupling comprises a set of discs the first of which after nearly one revolution picks up the next, and so on. When the maximum amount of allowed debit is reached the lost motion in the coupling 20 is completely taken up and a stop plate 20C is rotated anticlockwise to displace a lever system 22, 22B. Lever 22B releases a spring motor 23, 23A, 23B, which drives a contact operating cam (not shown) at a speed controlled by an air vane 24. The cam opens the contacts for a short time sufficient to break the connection with the exchange. The contacts are remade to enable emergency calls to be set up unhindered by the existing maximum debit. To prevent the establishment of non-emergency calls in this state of debit a pin on the credit/debit indicator makes a set of contacts to short the impulse contacts. Emergency calls involve the use of the normal auxiliary springs. To cope with conditions of maximum credit the lost motion coupling takes up slack in the opposite direction and rotates the stop plate 20C clockwise to release a catch lever 21 which engages the ratchet drive arm 11 and holds it out of range of the driving cam 10B. As the quantity mechanism is debited the lost motion coupling goes slack and the drive arm 11 is released. Whenever further credit is deposited after the spring motor 23, 23A, 23B, has unwound to release a connection, the ratchet drive arm 11 engages the lever 23 to rewind the motor. Debit pulses from the exchange energize the windings shown at the top of Fig. 1, and, by drawing into alignment an armature normally biased out of alignment of polepieces, control an escapement mechanism, Figs. 5, 6 or 7 (not shown), to step the quantity mechanism in debit direction. An alternative coin mechanism may be employed, coins being inserted through the face of a rotatable carriage plate as in the normal gas meter mechanism, Figs. 18 to 22 (not shown). In this mechanism coins deflect a bell crank lever proportionally to their value and the bell crank deflects a ratchet drive lever to set the quantity mechanism. The ratchet drive lever is latched out of range by the lost-motion mechanism as before when maximum coins have been received. At maximum allowed debit the lost-motion mechanism releases an escapement mechanism one tooth thereby allowing a cam to open the line contacts for a short time. The escapement is powered by a slipping spring store wound through a ratchet which is stepped from the bell crank each time a coin is deposited. Debiting is effected as in the previous embodiment.